<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        /* 1.使用弹性盒子,必须在父盒子有足够的空间 
        2.父盒子设置 display:flex;
        3.主轴和侧轴的概念,主轴默认水平方向,侧轴默认垂直方向*/
        .box{
            width: 600px;
            height: 300px;
            border: 1px solid #000;
            /* 弹性盒子必须在父盒子上设置display: flex;*/
            /* display: flex;
            主轴的对齐方式,默认是start
            justify-content: start;
            justify-content: center;
            justify-content: end;
            两端对齐
            justify-content: space-between;
            四周环绕
            justify-content: space-around;
            均分
            justify-content: space-evenly;
            不能给高 拉伸 相当于默认值
            justify-content: stretch; */



            /* 侧轴对齐方向
            align-items: start;
            align-items: center;
            align-items: end;
            align-items: stretch;

            改变主轴或侧轴的方向
            flex-direction: column,row,row-reverse,column-reverse;

             换行后的对齐方式 algin-content要与flex-warp一起使用
            align-content: space-around;默认
            align-content: stretch; */
        }
        .inner{
            height: 100px;
            width: 100px;
            border: 1px solid #000;
            font-size: 50px;
            line-height: 100px;
            text-align: center;
            box-sizing: border-box;
        }
    </style>
</head>
<body>
    <div class="box">
        <div class="inner">1</div>
        <div class="inner">2</div>
        <div class="inner">3</div>
    </div>
</body>
</html>